The present invention relates generally to automotive exhaust systems and, in particular, to a sound dampening assembly for an automotive exhaust system.
Automotive exhaust systems include piping and other components that treat an exhaust gas stream as well as rout the stream from an inlet connected to an internal combustion engine to an outlet to atmosphere.
Mufflers are disposed in the exhaust systems and are intended to smooth the exhaust gas pulsations and make the noise emitting from the tail pipe as inaudible as possible. To dampen and smooth the exhaust gas pulsations, mufflers and/or resonators use a combination of reflection and absorption techniques typically employing such traditional elements as helmholtz resonators, pipes perforated with holes and venturi nozzles. These traditional elements are sized and dimensioned (i.e. tuned) to have specified natural frequencies. These tuning elements, then, will dampen the frequencies of interest within the exhaust gas stream. Often, however, additional or unexpected noises occur in the exhaust system. These noises must also be dampened to minimize noises felt or heard in the passenger compartment and to assure compliance with noise regulations. Moreover, packaging concerns remain an issue in the design of the exhaust system because these traditional tuning elements consume a relatively large amount of space in the vehicle, which space in the vehicle and in the engine compartment in particular is limited.
It is desirable, therefore, to provide an effective sound dampening assembly for an automotive exhaust system that may be packaged easily within the engine compartment.